Proofread the following extracts and correct any errors in verb tenses. correct the single error in this paragraph: the ancient chinese board game “go” is invented long before there was any writing to record its rules. a game from the impossibly distant past has now brought us closer to a moment that once seemed part of an impossibly distant future: a time when machines are cleverer than we are. correct the two errors in these paragraphs: for years, go was considered the last redoubt against the march of computers. machines might win at chess, draughts, othello, three-dimensional noughts and crosses, monopoly, bridge, and poker. go, though, is different. the game required intuition, strategising and character reading, along with vast numbers of moves and permutations. according to legend, it was invented by a chinese emperor to teach his subjects balance and patience: qualities unique to human intelligence. correct the two errors in these paragraphs: this week, though, a computer called alpha go defeats the world’s best player of go. it did so by “ learning” the game, crunching through 30 million positions from recorded matches, reacting and anticipating. it evolves as a player and taught itself. that single game of go marks a milestone on the road to the “technological singularity”, the moment when artificial intelligence becomes capable of self-improvement and learns faster than humans can control or understand. , you!

1- The ancient Chinese board game “Go” is invented long before there was any writing to record its rules. A game from the impossibly distant past has now brought us closer to a moment that once seemed part of an impossibly distant future: a time when machines are cleverer than we are.

Because it's an action that started and finished in the past, this should read was (Simple Past)

2- For years, Go was considered the last redoubt against the march of computers. Machines might win at chess, draughts, Othello, three-dimensional noughts and crosses, Monopoly, bridge, and poker. Go, though, is different.

This continues the same line of mistake as the first paragraph. Because it's referencing something that already happened ("Go was considered...), this should read was (Simple Past).

The game required intuition, strategising and character reading, along with vast numbers of moves and permutations. According to legend, it was invented by a Chinese emperor to teach his subjects balance and patience: qualities unique to human intelligence.

The conjunction and is used before the last element in a list. In this case, this word should be substituted by a comma because character reading is not the last element on that list.

3- This week, though, a computer called Alpha Go defeats the world’s best player of Go. It did so by “ learning” the game, crunching through 30 million positions from recorded matches, reacting and anticipating. It evolves as a player and taught itself.

That single game of Go marks a milestone on the road to the “technological singularity”, the moment when artificial intelligence becomes capable of self-improvement and learns faster than humans can control or understand.

These should read defeated ... evolved. This continues the same line of thought on subject-verb agreement. If it's talking about a past event, and the rest of the paragraph sustains that idea, then these verbs should be in Simple Past.